Genetic associations with education have increased over time and are patterned by socioeconomic background: a cross-cohort analysis of three British studies born 1946 to 1970

Social scientists have long sought to investigate whether the predictors of educational attainment have changed across time. Here, we provide new insights by incorporating genetic predictors of education in three nationally representative British birth cohorts born in 1946, 1958 and 1970. We investigated whether individual characteristics as proxied by a polygenic index for educational attainment (EA PGI) have become more relevant to educational success over time, and whether returns to genetic endowments were moderated by early life socioeconomic background. We present three novel findings. First, the EA PGI explained a larger proportion of variation in years of education over time, rising from 5.4% for the 1946 cohort to 5.7% in the 1958 cohort and 5.9% in the 1970 cohort. Second, patterns using a PGI for cognition were in the opposite direction to those with the EA PGI; 2.1% in 1946c to 1.6% in 1958c and 1.0% in 1970c. Given that the EA PGI captures multiple traits related to educational success simultaneously, only some of which may be considered meritorious, this cautions against interpretations that reductions in the explanatory power of the EA PGI over time simply reflect increasing meritocracy. Third, we observed strong evidence of interaction: associations between the EA PGI and educational attainment were disproportionately larger amongst those from more advantaged socioeconomic backgrounds. Our findings are consistent with educational attainment being influenced by social and genetic factors both independently and jointly. Genetic liability and social background could be considered as two forms of inherited advantage which synergistically influence education attainment.